In many office buildings, when new tenants move in or the communications requirements of existing tenants change, new communications wiring is installed. New wiring is preferred in many cases despite the existence of already installed wiring which could meet the new requirements and despite the significant expense involved in installing new wiring. One reason that new wiring is often installed is that records identifying the termination points of the existing wiring frequently do not exist or, if such records have been established, their current accuracy is questionable. This problem has become exacerbated by the divestiture of the Bell system, which previously managed this record keeping function, and the assumption of wiring management responsibilities by building owners and tenants. Often, such owners or tenants do not have the skill or the facilities to satisfactorily perform this management function.
The task of identifying the termination points at remote building locations with terminals in a central wiring closet and, thus, the communication paths between them may be considered as a point mapping problem within a given topology.
The general topology for two sets of such points is shown in FIG. 1. Communications paths 3 connect the set of points 1 with the set of points 2. Such paths could be, for example, wires, coaxial cables, optical fibers or optical beams. Each set of points 1 and 2 may be physically dispersed or partially or completely centralized. In addition, each set of points may be either intermediate or end terminations of the paths 3.
Traditional means for mapping the connectivity between points 1 and 2 when the paths 3 are telephone lines, such as those installed in commercial buildings, have involved a tone generator, a telephone receiver and two technicians. The first technician connects the tone generator to one of the points 1. The second technician sequentially connects and disconnects the telephone receiver to each of the points 2 until the tone generator signal is heard. The second technician then communicates, typically through an auxiliary communications channel such as a hand held radio, that he has acquired the tone and requests that the first technician identify the current physical location (such as a room number) of the tone generator. The second technician then typically labels the particular point 2 at which the tone was heard with the physical location information supplied by the first technician. The first technician then moves to the next point 1 and repeats the process. The labels thereby generated are the equivalent of a map of the connectivity between points 1 and 2.
An improvement to this traditional method may be seen in U.S. Pat. No. 4,916,444 (King), entitled METHOD AND APPARATUS FOR MAPPING COMMUNICATIONS MEDIA, and assigned to the assignee of the present invention, whose teachings are incorporated herein by reference.
In the described method and apparatus of the referenced patent, as seen with reference to FIG. 1, a first apparatus is connected at points 1 and has some detectable characteristic for identifying the physical location of such apparatus. The preferred embodiment discussed in that patent contemplated a temporary or permanent, but separate, apparatus for each of points 1, each such apparatus being operative to generate a code or signal uniquely related to such respective point; the unique code signal being correlated in a data base with the respective point. A second apparatus is connected temporarily or permanently to points 2 and detects such characteristic of the first apparatus connected at points 1. It has a structure for identifying the physical location of specific points 2 where the specific characteristic of points 1 are detected. A third apparatus employs a process which correlates information about the physical location of the first apparatus connected to points 1 with the physical locations of the specific connections at points 2 at which the characteristics of the first apparatus at points 1 are detected such that the connectivity between the physical locations of points 1 and points 2 can be determined.
As described therein, the first apparatus connected at points 1 typically comprises plural sources of unique identifiers for each such point. Such identifiers can comprise different impedances or distinctive waveforms such as different frequencies or amplitudes or uniquely modulated or coded analog or digital signals.
The second apparatus connected at points 2 consists of one or more detectors of the unique identifiers employed by the first apparatus connected at points 1.
Finally, there is a third apparatus to record the particular points 2 at which a particular unique identifier was detected. The second apparatus may optionally include a switch or switches which sequentially connect a single detector to each of the points 2 or a switch or switches which sequentially connect the outputs of multiple detectors to a single data storage device. A further variation is the use of a switch or switches which sequentially connect multiple data storage devices to a single storage device.
The method disclosed in the referenced patent comprises three basic steps. Step 1 is to record in a first intermediate data base the relationship between unique identifiers and physical locations at point 1. For example, if the unique identifier is frequency and if room number 525 is a particular location of points 1 where apparatus which generates a frequency of 10 KHz has been connected, then this and each other such relationship are recorded.
Step 2 of the method consists of recording in a second intermediate data base the relationships between the unique identifiers detected at points 2 and the particular points 2 at which they were detected. For example, points 2 could be terminal blocks of an intermediate distribution frame for telephone wiring in a commercial building. If, as in the previous example, the unique identifier at points 1 is frequency and if 10 KHz was detected at pin pair 5-6 of terminal block A, then this information is recorded together with the particular frequencies detected at each other particular pin pair.
Step 3 of the method consists of correlating the information recorded in step 1 with the information recorded in step 2 such that the connectivity between the specific physical locations of points 1 and the specific physical locations of points 2 is generated as a third mapping data base. Using the previous example, the unique identifier frequency of 10 KHz is a common element of step 1 and step 2. Step 3 produces the result that room 525 is connected to pin pair 5-6 of terminal block A. This result is one element of the desired map of the connectivity between points 1 and 2.
Since the preferred embodiment of the referenced patent employs unique identifiers at each first location 1, the cost of implementing the system may be undesirably high, depending on the number of remote points being mapped. Moreover, the method of the preferred embodiment contemplates the creation of a first data base relating the unique identifier to each particular point 1 and a second data base relating the unique identifier to a particular point 2.